KA is being a B**** to smog!!! - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

ka707de · 10-20-2010, 07:43 PM

I have a 91 240 coupe with a KA24DE and a 3" down pipe. I am trying to get it smogged but it is marked a "gross polluter" because of the nox emissions. Also the EGR is throwing a check engine light. I replaced the broken vacuum tube I found but its still there. It is very difficult to look in at the EGR because the person before me replaced the wiring harness but left the old one still kindof hooked in... I have no idea why they would do that but... oh well.

If anyone can tell me if the EGR light specifically means nox emissions would be off, that would be great.

Another option would be if someone could point me in the right direction towards someone who could help me with passing smog... that would be great too. I live in the bay area and any help would be very much appreciated!!!

jdm213 · 10-20-2010, 10:23 PM

well first off look at your exhaust and you wont pass visual if you have the check engine light cuz thats an automatic fail

ka707de · 10-20-2010, 11:13 PM

I know I wont pass with the check engine light on. I was just asking if fixing the EGR will fix the nox emissions. it will pass visual but I just need to figure out how to fix the emissions or get it smogged someplace that wont care about any of that..

w0nderbr3ad · 10-20-2010, 11:41 PM

best bet would be to check the codes your ecu is throwing. check vacuum hoses and if you're nox is in the thousands you might want to get another catalytic converter.

klits562 · 10-21-2010, 05:44 PM

IIRC the egr is suppose to reduce NOX but at freeway speeds. Did the smog place tell you how high your NOX was and at wat speed?
If the EGR is throwing a code you need to check it see if its working. If its working fine then you need to clean it and any lines that go from exhaust->EGR->intake. Same thing happend to my brothers lancer.

reflexdb · 10-21-2010, 06:39 PM

Your EGR or "Exhaust Gas Recirculation" Valve opens to let exhaust flow back into the intake, which reduces your combustion temperature and hence your NOx production amount.

Yeah, you're going to want the EGR Valve to work in order to reduce NOx.

ka707de · 10-22-2010, 03:28 AM

It has a brand new cat so thats not the problem, the check engine light is on because it threw the EGR code and the knock sensor code (irrelevant), and would the EGR not functioning at all cause high nox emissions? or does it do nothing in low rpms and just kick in at high rpms.. I was pretty sure it was the EGR, but I just wanted someone to confirm my thoughts.

also does anyone have some good pictures of how the EGR is fully set up?

klits562 · 10-22-2010, 11:46 AM

Quote:

Originally Posted by ka707de

It has a brand new cat so thats not the problem, the check engine light is on because it threw the EGR code and the knock sensor code (irrelevant), and would the EGR not functioning at all cause high nox emissions? or does it do nothing in low rpms and just kick in at high rpms.. I was pretty sure it was the EGR, but I just wanted someone to confirm my thoughts.

also does anyone have some good pictures of how the EGR is fully set up?

The EGR opens under vacuum at higher speeds which is why i asked you; your nox numbers and at what mph. This will help us help you and let you know if its your EGR or not.

Also if you dont know what the EGR looks like just go on Autozone and find look at the pic its easy to find and it bolts onto the back of your intake manifold.

modulation · 10-23-2010, 09:14 PM

Quote:

Originally Posted by ka707de

I have a 91 240 coupe with a KA24DE and a 3" down pipe. I am trying to get it smogged but it is marked a "gross polluter" because of the nox emissions. Also the EGR is throwing a check engine light. I replaced the broken vacuum tube I found but its still there. It is very difficult to look in at the EGR because the person before me replaced the wiring harness but left the old one still kindof hooked in... I have no idea why they would do that but... oh well.

If anyone can tell me if the EGR light specifically means nox emissions would be off, that would be great.

Another option would be if someone could point me in the right direction towards someone who could help me with passing smog... that would be great too. I live in the bay area and any help would be very much appreciated!!!

Make sure you have NO exhaust leaks. Really high NOX would point to an exhaust leak Pre-cat. That was my problem.

ka707de · 10-24-2010, 01:57 AM

exaust line is all solid, no leaks. i know what the egr looks like i was asking if anyone had pictures because i want to see how the vacuum hoses hook up and where all the other stuff is hooked up in the back of the engine because its really jenky from the person before messing with it..

the nox readings were 2002 at 15 mph and 1802 at 25

modulation · 10-24-2010, 10:54 AM

Quote:

Originally Posted by ka707de

exaust line is all solid, no leaks. i know what the egr looks like i was asking if anyone had pictures because i want to see how the vacuum hoses hook up and where all the other stuff is hooked up in the back of the engine because its really jenky from the person before messing with it..

the nox readings were 2002 at 15 mph and 1802 at 25

Dude you have an exhaust leak some where.
The only thing that would cause NOX numbers that high is that air is getting in before the cat. This causes the CAT to burn ultra-efficient and raises the temp of the air high enough to cause NOx.

I bet your Co2 and other hydrocarbon numbers are really really low.

Double check your header gasket, and your gasket between your header and your cat.

Rabboni · 10-24-2010, 05:59 PM

If you want your nox emissions to go down you will definitely have to fix your egr. if you fix your egr, your nox emissions should go down enough for you to pass.

singlecamslam · 10-24-2010, 06:11 PM

lift up your egr diaphram manually while the car is running, does the engine begin to die? Rev your engine while placing your hand on the diaphram, does it go up? I have a similar problem where my egr makes the egine die but doesnt raise when the car is revved for some reason.

ka707de · 10-25-2010, 10:23 AM

So i found out through diagrams (that i had been to lazy to look up) that the guy before me thought to disable the egr by breaking off the egr sensor module... i dont know why he didnt just unplug it but its gone and i have to go get a new one..

Quote:

Originally Posted by modulation

Dude you have an exhaust leak some where.
The only thing that would cause NOX numbers that high is that air is getting in before the cat. This causes the CAT to burn ultra-efficient and raises the temp of the air high enough to cause NOx.

I bet your Co2 and other hydrocarbon numbers are really really low.

Double check your header gasket, and your gasket between your header and your cat.

well my CO2 measured a 14.73 and 13.9 and the hc was 36 and 34. still possible for exhaust leak or too high?

modulation · 10-25-2010, 07:44 PM

Quote:

Originally Posted by ka707de

So i found out through diagrams (that i had been to lazy to look up) that the guy before me thought to disable the egr by breaking off the egr sensor module... i dont know why he didnt just unplug it but its gone and i have to go get a new one..

well my CO2 measured a 14.73 and 13.9 and the hc was 36 and 34. still possible for exhaust leak or too high?

What are the max again? Like 100 or something?
Is it possible the EGR tube is letting air into the exhuast?

ka707de · 10-26-2010, 01:28 AM

it is very possible since there are open ended vacuum tubes around the egr because that peice is gone. i got the sensor at pick n pull today and will be installing it tomorrow. But once that piece is in, if it turns the check engine code for the egr off, then it should pass smog right?

godrifttoday · 10-26-2010, 01:51 AM

can u just pay a little extra and get it smogged? you know " LEGIT"

ka707de · 10-26-2010, 07:08 PM

I've asked around but noone knows of any near me that will do that.. so until then i am gunna continue trying to fix whats wrong. pm me if you know one

10-20-2010, 07:43 PM	#1
ka707de Join Date: Aug 2010 Location: petaluma,ca Posts: 12 Trader Rating: (0) Feedback Score: 0 reviews	KA is being a B to smog!!! I have a 91 240 coupe with a KA24DE and a 3" down pipe. I am trying to get it smogged but it is marked a "gross polluter" because of the nox emissions. Also the EGR is throwing a check engine light. I replaced the broken vacuum tube I found but its still there. It is very difficult to look in at the EGR because the person before me replaced the wiring harness but left the old one still kindof hooked in... I have no idea why they would do that but... oh well. If anyone can tell me if the EGR light specifically means nox emissions would be off, that would be great. Another option would be if someone could point me in the right direction towards someone who could help me with passing smog... that would be great too. I live in the bay area and any help would be very much appreciated!!!

10-21-2010, 06:39 PM	#6
reflexdb Zilvia Junkie Join Date: Feb 2004 Location: Denver, CO Age: 39 Posts: 381 Trader Rating: (6) Feedback Score: 6 reviews	Your EGR or "Exhaust Gas Recirculation" Valve opens to let exhaust flow back into the intake, which reduces your combustion temperature and hence your NOx production amount. Yeah, you're going to want the EGR Valve to work in order to reduce NOx. __________________

10-24-2010, 05:59 PM	#12
Rabboni Zilvia Member Join Date: Aug 2009 Location: Fairfield, CA Posts: 230 Trader Rating: (0) Feedback Score: 0 reviews	If you want your nox emissions to go down you will definitely have to fix your egr. if you fix your egr, your nox emissions should go down enough for you to pass. __________________ Baling Wire-The Duct Tape Of Champions

10-24-2010, 06:11 PM	#13
singlecamslam Post Whore! Join Date: Apr 2008 Location: Norcal Posts: 2,534 Trader Rating: (10) Feedback Score: 10 reviews	lift up your egr diaphram manually while the car is running, does the engine begin to die? Rev your engine while placing your hand on the diaphram, does it go up? I have a similar problem where my egr makes the egine die but doesnt raise when the car is revved for some reason. __________________ Nothing says racecar like a stock car with no interior.

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10-20-2010, 10:23 PM	#2
jdm213 Zilvia Addict Join Date: Sep 2009 Location: los angeles Age: 33 Posts: 960 Trader Rating: (10) Feedback Score: 10 reviews	well first off look at your exhaust and you wont pass visual if you have the check engine light cuz thats an automatic fail

10-20-2010, 11:13 PM	#3
ka707de Join Date: Aug 2010 Location: petaluma,ca Posts: 12 Trader Rating: (0) Feedback Score: 0 reviews	I know I wont pass with the check engine light on. I was just asking if fixing the EGR will fix the nox emissions. it will pass visual but I just need to figure out how to fix the emissions or get it smogged someplace that wont care about any of that..

10-20-2010, 11:41 PM	#4
w0nderbr3ad Zilvia FREAK! Join Date: Feb 2004 Location: Vantucky Posts: 1,294 Trader Rating: (50) Feedback Score: 50 reviews	best bet would be to check the codes your ecu is throwing. check vacuum hoses and if you're nox is in the thousands you might want to get another catalytic converter.

10-21-2010, 05:44 PM	#5
klits562 Zilvia Member Join Date: Aug 2010 Location: Norwalk, CA Age: 33 Posts: 152 Trader Rating: (0) Feedback Score: 0 reviews	IIRC the egr is suppose to reduce NOX but at freeway speeds. Did the smog place tell you how high your NOX was and at wat speed? If the EGR is throwing a code you need to check it see if its working. If its working fine then you need to clean it and any lines that go from exhaust->EGR->intake. Same thing happend to my brothers lancer.

10-22-2010, 03:28 AM	#7
ka707de Join Date: Aug 2010 Location: petaluma,ca Posts: 12 Trader Rating: (0) Feedback Score: 0 reviews	It has a brand new cat so thats not the problem, the check engine light is on because it threw the EGR code and the knock sensor code (irrelevant), and would the EGR not functioning at all cause high nox emissions? or does it do nothing in low rpms and just kick in at high rpms.. I was pretty sure it was the EGR, but I just wanted someone to confirm my thoughts. also does anyone have some good pictures of how the EGR is fully set up?

10-24-2010, 01:57 AM	#10
ka707de Join Date: Aug 2010 Location: petaluma,ca Posts: 12 Trader Rating: (0) Feedback Score: 0 reviews	exaust line is all solid, no leaks. i know what the egr looks like i was asking if anyone had pictures because i want to see how the vacuum hoses hook up and where all the other stuff is hooked up in the back of the engine because its really jenky from the person before messing with it.. the nox readings were 2002 at 15 mph and 1802 at 25

10-26-2010, 01:28 AM	#16
ka707de Join Date: Aug 2010 Location: petaluma,ca Posts: 12 Trader Rating: (0) Feedback Score: 0 reviews	it is very possible since there are open ended vacuum tubes around the egr because that peice is gone. i got the sensor at pick n pull today and will be installing it tomorrow. But once that piece is in, if it turns the check engine code for the egr off, then it should pass smog right?

10-26-2010, 01:51 AM	#17
godrifttoday Post Whore! Join Date: Jan 2004 Location: los angeles Age: 40 Posts: 3,120 Trader Rating: (82) Feedback Score: 82 reviews	can u just pay a little extra and get it smogged? you know " LEGIT"

10-26-2010, 07:08 PM	#18
ka707de Join Date: Aug 2010 Location: petaluma,ca Posts: 12 Trader Rating: (0) Feedback Score: 0 reviews	I've asked around but noone knows of any near me that will do that.. so until then i am gunna continue trying to fix whats wrong. pm me if you know one